Verdi's slave girl (4)
I believe the answer is:
aida
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">verdi's slave girl</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for aida that I've seen before include "Covent Garden production?" , "work of grand proportions" , "Princess" , "she dies entombed" , "Verdi opera" .)